To deal with anger, the first thing you need to do is knowing that you are angry.

People let their emotions and voices in head (mind) control them.
They unconsciously choose to do whatever their emotions and inner chatter tell them to do.
To deal with your “inner” self,
you have to observe your mind and emotion with your consciousness.
By doing so you start to become aware of your mind and emotion.

(for example) Many people who get angry do not really realise that they are in the state of anger.
They simply do whatever that comes into their mind and emotion.
They lack the will to control themselves.

Whenever you face negative emotions,
simply observe your inner state
as if you are the third party who observes your mind and feelings.
Observe and realise that you are in negative state.

After that calm down and choose to let go all attachment towards the negativity.
Do not think of the things (stimulus) that cause the negativity.
Think of something positive,
like imagine lying down gently and happily in warm water.
Choose to control your mind and emotion.
Gradually you will develop will power to overcome yourself.

A good exercise to deal with yourself is meditation.
While meditating, we are focusing and observing something with our consciousness.
The inner chatter (mind) and emotion will arise
and we will have to observe them with our consciousness.
After that we either choose to ignore them or having control over them.
Simply apply what you do in meditation in real life and learn to control yourself.

It is not easy to conquer yourself at first but practice makes perfect.
Being able to deal with yourself is an important step to control your own life.